Method for producing a liquid crystal device with low zenithal anchoring energy, and resulting device

ABSTRACT

A method of making nematic liquid crystal devices where low energy zenith anchoring of the liquid crystal is obtained over confinement plates. A polymer or copolymer is deposited based on PVC onto a substrate. The polymer deposit is stabilized. An azimuth orientation is defined for the deposit to induce controlled azimuth anchoring of the liquid crystal.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a seat belt electromagnetic lock for use in connection with seat belt retractor. The seat belt electromagnetic lock has particular utility in connection with an electrically actuatable locking mechanism for locking a seat belt retractor to prevent withdrawal of seat belt webbing.

2. Description of the Prior Art

Seat belt electromagnetic locks are desirable for preventing serious injury in the event of a traffic accident. News sources tell us that approximately fifty thousand people are killed in traffic accidents each year, many occur due to side impacts and some occur due to untensioned seat belts. Current seat belt designs only work properly if the belt is tensioned around the individual, due to intermittent locking a tension eliminator device was added to seat belts. If the tension eliminator is misused and a belt is pulled out more than necessary then it becomes ineffective. A need was felt to remove the tension eliminator while ensuring a good seat belt fit. Current seat belt designs also do not adequately address the need for side impact protection. Therefore the new design was made to meet both needs, a safe comfortable seat belt fit, and protection in the event of a side impact.

The use of seat belt retractor is known in the prior art. For example, U.S. Pat. No. 3,797,603 to Loomba discloses an electromagnetically controlled seat belt retractor that is a reel type retractor for a safety belt having the feature that an electromagnet, normally activated and holds a cam member by virtue of an armature attached thereto. This armature maintains a pawl out of latching engagement with the reel, thereby permitting free engagement with the reel, thereby permitting free extension of the belt. Any interruption of the current to the electromagnet permits the reel to rotate the cam, releasing a cam follower attached to the pawl bar, and allowing the biased pawl bar to rotate into locking engagement with the reel. However, the Loomba '603 patent does not include a locking wheel which has cylindrical locking bores, nor does it have cylindrical locking pins which fit within the locking bores, nor does it have a locking key that holds the locking pin within the locking bore, nor does it include a seat belt attached at the bottom central part of the seat, with the belt divided into two parts near the top of the back of the seat with one section extending downward over each side of the front of the seat.

Similarly, U.S. Pat. No. 4,895,317 to Rumpf et al discloses an electrically actuatable locking mechanism for a seat belt retractor that comprises a spindle having seat belt webbing wound thereon. The spindle is supported for the rotation in belt withdrawal and belt retraction directions. A member is moveable between a first position in which the spindle is free to rotate in the belt withdrawal direction a second position in which the spindle is blocked from rotating in the belt withdrawal direction. A permanent magnet is fixed to the member. An energizable electromagnet includes a core locate adjacent the permanent magnet for attracting the permanent magnet for attracting the permanent magnet to thereby move the member to one of its first and second positions when the electromagnet is de-energized. The core repels the permanent magnet to thereby move the member to the other one of its first and second positions upon energization of said electromagnet. However, the Rumpf et al '317 patent does not include a locking wheel which has cylindrical locking bores, nor does it have cylindrical locking pins which fit within the locking bores, nor does it have a locking key that holds the locking pin within the locking bore, nor does it include a seat belt attached at the bottom central part of the seat, with the belt divided into two parts near the top of the back of the seat with one section extending downward over each side of the front of the seat.

Lastly, U.S. Pat. No. 4,427,216 to Kato et al discloses a seat belt tensioning device that comprises a cylinder, a piston that is slidably inserted within the cylinder. A rod connects the piston and the seat belt. A piston pushing means is provided within the cylinder for applying driving force to the piston. A trigger means comprises a plurality of rings and balls interposed between opposing rings. The trigger means is provided in the cylinder for usually locking the rod into the cylinder overcoming the driving force of the piston pushing means and releasing the rod from the cylinder to allow the movement of the piston only at an urgent time. A driving means drives the trigger means to release the rod from the cylinder at an urgent time. However, the Kato et al '216 patent does not include a locking wheel which has cylindrical locking bores, nor does it have cylindrical locking pins which fit within the locking bores, nor does it have a locking key that holds the locking pin within the locking bore, nor does it include a seat belt attached at the bottom central part of the seat, with the belt divided into two parts near the top of the back of the seat with one section extending downward over each side of the front of the seat.

While the above-described devices fulfill their respective, particular objectives and requirements, the aforementioned patents do not describe a seat belt electromagnetic lock that allows an electrically actuatable locking mechanism for locking a seat belt retractor to prevent withdrawal of seat belt webbing. The Loomba '603, Rumpf et al '317, and Kato et al '216 patents make no provision for including a locking wheel which has cylindrical locking bores, nor do they have cylindrical locking pins which fit within the locking bores, nor do they have a locking key that holds the locking pin within the locking bore, nor do they include a seat belt attached at the bottom central part of the seat, with the belt divided into two parts near the top of the back of the seat with one section extending downward over each side of the front of the seat.

Therefore, a need exists for a new and improved seat belt electromagnetic lock that can be used for an electrically actuatable locking mechanism for locking a seat belt retractor to prevent withdrawal of seat belt webbing. In this regard, the present invention substantially fulfills this need. In this respect, the seat belt electromagnetic lock according to the present invention substantially departs from the conventional concepts and designs of the prior art, and in doing so provides an apparatus primarily developed for the purpose of an electrically actuatable locking mechanism for locking a seat belt retractor to prevent withdrawal of seat belt webbing.

SUMMARY OF THE INVENTION

In view of the foregoing disadvantages inherent in the known types of seat belt retractor now present in the prior art, the present invention provides an improved seat belt electromagnetic lock, and overcomes the above-mentioned disadvantages and drawbacks of the prior art. As such, the general purpose of the present invention, which will be described subsequently in greater detail, is to provide a new and improved seat belt electromagnetic lock and method which has all the advantages of the prior art mentioned heretofore and many novel features that result in a seat belt electromagnetic lock which is not anticipated, rendered obvious, suggested, or even implied by the prior art, either alone or in any combination thereof.

To attain this, the present invention essentially comprises a locking wheel, the locking wheel having an outer edge, the locking wheel having multiple radial bores in its outer edge. A locking pin has a shape that is complementary to the locking wheel radial bore, for selectively fitting within the radial bore. A pin driver applies driving force to the locking pin. A removable locking key retains the locking pin in the locking wheel radial bore. A seat belt spindle is connected to the locking wheel. A seat belt is connected to the seat belt spindle. The seat belt attached at the bottom central part of the seat, the seat belt is divided into two sections near the top of the back of the seat, the seat belt sections extend downward over each side of the front of the seat.

There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood and in order that the present contribution to the art may be better appreciated. The invention may also include a mounting base, a housing, a lock switch and a power connection. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject matter of the claims attached.

Numerous objects, features and advantages of the present invention will be readily apparent to those of ordinary skill in the art upon a reading of the following detailed description of presently preferred, but nonetheless illustrative, embodiments of the present invention when taken in conjunction with the accompanying drawings. In this respect, before explaining the current embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein are for the purpose of descriptions and should not be regarded as limiting.

As such, those skilled in the art will appreciate that the conception, upon which this disclosure is based, may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention.

It is therefore an object of the present invention to provide a new and improved seat belt electromagnetic lock that has all of the advantages of the prior art seat belt retractor and none of the disadvantages.

It is another object of the present invention to provide a new and improved seat belt electromagnetic lock that may be easily and efficiently manufactured and marketed.

An even further object of the present invention is to provide a new and improved seat belt electromagnetic lock that has a low cost of manufacture with regard to both materials and labor, and which accordingly is then susceptible of low prices of sale to the consuming public, thereby making such seat belt electromagnetic lock economically available to the buying public.

Still another object of the present invention is to provide a new seat belt electromagnetic lock that provides in the apparatuses and methods of the prior art some of the advantages thereof, while simultaneously overcoming some of the disadvantages normally associated therewith.

Even still another object of the present invention is to provide a seat belt electromagnetic lock for an electrically actuatable locking mechanism for locking a seat belt retractor to prevent withdrawal of seat belt webbing.

Still yet another object of the present invention is to provide a seat belt electromagnetic lock that eliminates the tension eliminator device to increase seat belt effectiveness.

Lastly, it is an object of the present invention is to provide a seat belt electromagnetic lock that eliminates the energy absorbing plastic shaft or pendulum actuator of current seat belt designs which only function properly when no slack is present in the seat belt.

These together with other objects of the invention, along with the various features of novelty that characterize the invention, are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and the specific objects attained by its uses, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated preferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:

FIG. 1 is a front side view of the preferred embodiment of the seat belt electromagnetic lock constructed in accordance with the principles of the present invention.

FIG. 2 is a rear side view of the seat belt electromagnetic lock of the present invention.

FIG. 3 is a section 3 view of FIG. 1 of the seat belt electromagnetic lock of the present invention.

FIG. 4 is a section 4—4 view of FIG. 3 of the seat belt electromagnetic lock of the present invention.

FIG. 5 is a section view of a conventional seat belt retractor.

The same reference numerals refer to the same parts throughout the various figures.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, and particularly to FIGS. 1–5, a preferred embodiment of the seat belt electromagnetic lock of the present invention is shown and generally designated by the reference numeral 10.

In FIG. 1, a new and improved seat belt electromagnetic lock 10 of the present invention for the electrically actuatable locking mechanism for locking the seat belt retractor to prevent withdrawal of seat belt webbing is illustrated and will be described. More particularly, the seat belt electromagnetic lock 10 has a seat belt 26. The seat belt 26 sections extending downward over each side 38 of a front 36 of a seat 28. A housing 46 is connected to a mounting base 44. A lock switch 40 is connected to the housing 46.

In FIG. 2, the seat belt electromagnetic lock 10 of the present invention is illustrated and will be described. The seat belt electromagnetic lock 10 has the seat belt 26. The seat belt 26 is attached at a bottom 30 central part of the seat 28. The seat belt 26 is divided into two sections near a top 32 of a back 34 of the seat 28. The housing 46 is connected to the mounting base 44. The lock switch 40 is connected to the housing 46.

In FIG. 3, the seat belt electromagnetic lock 10 of the present invention is illustrated and will be described. A locking wheel 14 has an outer edge 16 and a plurality of radial bores 18 disposed within the outer edge 16. A locking pin 20, which is magnetic in the present example, has the shape that is complementary to the locking wheel radial bore 18, for selectively fitting within the radial bore 18. A electromagnet pin driver 22 applies driving force to the locking pin 20. A removable locking key 24 retains the locking pin 20 in the locking wheel 14 radial bore. The lock switch 40 is electrically connected to the pin driver 22. A power connection 42 is electrically connected to the lock switch 40. The mounting base 44 is rotatably connected to the locking wheel 14. The housing 46 is connected to the mounting base 44.

In FIG. 4, the seat belt electromagnetic lock 10 of the present invention is illustrated and will be described. The locking wheel, which is ferrous in the present example, is connected to a seat belt spindle 12. The locking wheel 14 has the outer edge 16 and the radial bores 18 disposed within the outer edge 16. The magnetic locking pin 20 has the shape that is complementary to the locking wheel radial bore 18, for selectively fitting within the radial bore 18. The electromagnet pin driver 22 applies driving force to the locking pin 20. The removable locking key 24 retains the locking pin 20 in the locking wheel 14 radial bore. The seat belt 26 is connected to the seat belt spindle 12. The mounting base 44 is rotatably connected to the locking wheel 14. The housing 46 is connected to the mounting base 44.

In FIG. 5, a conventional seat belt retractor 48 is shown. The present invention can be connected to the seat belt spindle 12.

In use, it can now be understood that the electromagnetic lock seat belt differs from conventional seat belt use in that the lock switch 40 is pushed after the seat belt buckle is snapped closed. The lock switch 40 energizes the electromagnetic pin driver 22 forcing the locking pin 20 into the locking wheel radial bore 18 which secures the seat belt. If additional security is required a locking key 24 may be inserted into the housing 46 which will lock the locking pin 20 into the locking wheel radial bore 18.

While a preferred embodiment of the seat belt electromagnetic lock has been described in detail, it should be apparent that modifications and variations thereto are possible, all of which fall within the true spirit and scope of the invention. With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. For example, any suitable sturdy material such composite material may be used instead of the metal described. Also, the electromagnetic seat belt lock can be used either in conjunction with a conventional seat belt retractor or used alone. And although an electrically actuatable locking mechanism for locking a seat belt retractor to prevent withdrawal of seat belt webbing have been described, it should be appreciated that the seat belt electromagnetic lock herein described is also suitable for locking any webbing or cord on a reel.

Therefore, the foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. 

1. A method of making a liquid crystal alignment layer for bistable nematic liquid crystal devices comprising two confinement plates provided respectively on both sides of a nematic liquid crystal layer, said liquid crystal alignment layer having a low zenithal and a strong azimuthal anchoring energies for the liquid crystal layer over at least one of its confinement plates, said method comprising: depositing a copolymer of Poly(vinyl chloride) and poly(vinylacetate), to form said liquid crystal alignment layer, onto one of the two confinement plates; stabilizing the polymer deposit, the stabilization comprising at least one thermal annealing step at a temperature below the melting point and higher than the vitreous transition temperature of the polymer deposit and an ultraviolet light exposure in the range of 180 nm to 400 nm after said thermal annealing; and defining an azimuth orientation for the deposit to induce strong and controlled azimuth anchoring of the liquid crystal, the zenithal anchoring being characterized by a critical electric field for breaking the anchoring below 10 V/μm, the azimuthal anchoring being characterized by an extrapolation length less than 100 nm.
 2. The method according to claim 1 wherein the polymer is a terpolymer of Poly(vinylchloride-co-vinylacetate).
 3. The method according to claim 2, wherein the polymer is a terpolymer of Poly(vinylchloride-co-vinylacetate) in which the third monomeric unit is hydroxypropyl acrylate or vinyl alcohol.
 4. The method according to claim 1 wherein the stabilization implements at least one heating step of thermal annealing and said heating is performed for a duration of about 1 h
 30. 5. The method according to claim 1 wherein said defining controlled azimuth anchoring of the liquid crystal is performed by rubbing the polymer with a textile-covered roller.
 6. The method according to claim 1 wherein the polymer is deposited on the confinement plate by centrifuging. 